The present invention relates to a global positioning system (GPS) navigation device used for navigating a vehicle to a waypoint. More particularly, the invention is directed toward a navigation device that may be used for navigating an aircraft while providing aircraft instrument style displays.
Over past several decades, GPS based navigation devices have been increasingly used for navigation of vehicles along airways, waterways and roadways. This is as a result of the relative compactness, light weight, reliability and accuracy of these devices compared to traditional navigational aids such as UHF and VHF receivers.
In the aviation industry, such prior art devices have been offered as fixed mounted units, commonly mounted in the panel of an aircraft. Other prior art devices have been configured for portability, allowing a user to move the device from one aircraft to another without an expensive installation. Such portable and fixed-mounted GPS navigation devices generally offer various display page options, including moving-map displays, and digital displays of navigation data. While these displays convey a great amount of information in a small amount of space, they are vastly different in style and more difficult to read than the mechanical aircraft instruments, such as altimeters and rate of climb indicators, that are common to aircraft, especially aircraft used to train new pilots.
Mechanical aircraft instruments often provide a circular plate bearing a circumferential scale and an indicator, such as a needle, pivotally mounted at the center of the plate. One advantage that these older instruments, such as an altimeter, have when compared to newer electronic instruments having digital readouts is that a pilot is able to glance at the older instrument and quickly understand a flight characteristic. For example, clockwise movement of the needle, in an altimeter, would mean that the aircraft is climbing. Conversely, counter-clockwise movement of the needle indicates a descent. The speed of needle movement is also directly proportional to the rate of climb or descent.
In the case of a digital readout of altitude, a pilot may perceive a climb or descent by noticing that the readout is changing, but the pilot would have to read and understand the digits displayed to determine if the aircraft was climbing or alternatively descending. Such an action diverts the pilot's attention away from other flight instruments and is more time consuming when compared to noticing the clockwise or counterclockwise movement of a mechanical instrument. This may result in a delay in initiating corrective action, for example, if the aircraft began a descent when level flight was desired.
While GPS navigation devices are not commonly used as a primary instrument to maintain a specified altitude, they are used in flying along a particular course to an intended destination. Mechanical instruments used for flying along a particular course include a directional gyro (DG) and a horizontal situation indicator (HSI). A DG conveys heading information via a rotating disc bearing a compass rose and a fixed pointer or lubber line indicating on the disc the heading that an aircraft is flying. An HSI integrates a DG with a combined course and deviation indicator used to indicate the intended course and deviation in degrees from the course. As with a mechanical altimeter, a mechanical DG or HSI is relatively easier to read than its digital counterpart.
The prior art navigation devices do not address the need for providing a display option that presents navigation data in a mechanical aircraft instrument style for relative ease in understanding certain flight characteristics, such as track, altitude, rate of turn and rate of climb or descent. In addition, the prior art does not address the need for a navigation device configured for use in various applications such as aviation, marine and automotive applications.